As an image forming apparatus in which general plain paper produced by applying no special processing to a sheet material can be used, image forming apparatuses employing various systems such as an electro-photographic system, an ink-jet system, and a thermal transfer system have already been widely spread. Nowadays, the image forming apparatus is called a multi-functional peripheral (MFP) because of functions thereof.
Many functions are added to the MFP according to requests of users. For example, there are known an MFP in which a stapler that can staple plural printouts with staples is integrally provided and an MFP to which a post-processing apparatus that can hold a large number of copies (a predetermined number is treated as one unit of copy) of printouts for each copy is connectable. In order to reduce a space for setting the MFP, a position where copy outputs and printouts are discharged is often set below an original scanning device and above an image forming section. Moreover, the MFP can be used in an integrated printer in a closed local area network (LAN) or can be used for output of data received by the MFP functioning as a facsimile (FAX). A function of a printer server may be given to the MFP.
Nowadays, in general, a mass storage device, for example, a hard disk drive (HDD) device is incorporated in the MFP in order to store a large amount of data (in the applications described above).
When a paper exit (discharge) tray is arranged on a lower surface of a scanning unit, since a user cannot see paper, the user cannot check presence or absence of the paper unless the user stoops down. The user cannot take out the paper either unless the user stoops down.
Since copy outputs and printouts are discharged to the lower surface of the scanning unit, heat tends to fill the unit, the discharged paper curls, or pieces of the discharged paper stick to one another. In some case, both the curl of the paper and the sticking of the paper occur.
When the paper exit tray is arranged on a side of a main body of the MFP, since paper is exited to the side of the main body, the user cannot take out the paper unless the user turns around.
As the main body is larger, it is more difficult to take out the paper. A larger setting area of the main body is required because of the paper discharge tray. When an option such as a finisher is attached, the paper discharge tray is not provided on the main body side.
For example, JP-A-2004-109646 proposes a finisher device including a main discharge tray and a sub-discharge tray. However, an example that two or more trays are arranged on the MFP is not disclosed.
Since both the sub-discharge tray and the main discharge tray are located on the side of an image forming apparatus main body shown in the above document, the user working near the image forming apparatus and a sheet medium processing apparatus is required to move in order to carry back (take out) a sheet (the user working near the image forming apparatus is required to take a forced posture in order to take out a sheet in that place).
On the other hand, since the HDD is mounted, on condition that a power SW (a main switch) that interrupts energization (supply of electric power) to the MFP main body in terms of hardware is not used except in an emergency, OFF control through an operation panel and a sub-power SW are also used to turn off a power supply (energization) after a system (an operation system) finishes operation.
The HDD has a large heating value and, moreover, the functions of the MFP itself are diversified. Therefore, heat generation from a control unit (a control block and a circuit board) is too large to be compared with those of printers and small copying machines in the past.